Antennae and the NW trees don't get along very well.  The trees almost always win. 

I have a rubber Comet antenna that I've used in the woods before.  It seems to withstand the trees pretty well.  My current method is to use the NR770 Diamond antenna with my mobile amp when I'm on the road or in open areas and then if I go in the heavy wooded areas, I just flip the NR770 over so it lays down and use my handheld by itself.

Most antennas come pre-tuned for a frequency. Some (from Larsen, etc) can be purchased untuned and you cut the antenna to match it to the frequency you want.

SWR is helpful for these antennas and you can adjust them for the specific frequency you want. They come with instructions on how much to cut off for which frequency. most of us will just buy a dual band antenna that is pre tuned and has a coil on the bottom for SWR reasons.

It is important to make sure you have a good groundplane (metal connection) to ensure you have good SWR on any antenna unless it has it's own.
 

Edit     btw, I am by no means an expert on this.  This is about the extent of knowledge I have on tuning an antenna and have only done it once.  Most won't need to do this if they buy a pre tuned antenna or really want to maximize their performance on specific frequencies.   John's information is great and seems accurate, most of us never take it to this step however.  I may try the CB SWR meter just for giggles.

I received a reply from one of the examiners at the Olympia site and thought I'd pass the info along in case any of you may be thinking about it.
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From AC7MG:  "Our examination sessions are open - meaning we do not require 
appointments.  Please visit our exam webpage 
[http://home.comcast.net/~oars-ve] for all (hopefully) details.

73,

- {name omitted}  [AC7MG]
  OARS exam staff
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Here's a lazy link to their info site:  home.comcast.net/~oars-ve

Lazy link to the FCC Registration Number sign up site, they say to have this number in-hand before showing up for an exam : fjallfoss.fcc.gov/coresWeb/publicHome.do

I'm not saying you do...  I'm saying that a normal antenna with a good groundplane will probably outperform one with a built in groundplane.

Mike -- Read the link John Parsons posted.

Do you have a meter for VHF?

The Antenna will make a huge difference, but you could lose 1db with the connector, still better though.

A new 50 watt mobile radio is $110-$150 at hamradio.com, used should be cheaper. A decent CB would be $50-100. The mobile will have better reach, better audio, and is a lot less cumbersome in the car.

I'd really recommend the mobile radio.

 

Edit:  I'll add a little quip to this.  My father used to tell me that you never regret buying the right tool.  When you are initially buying something you are relying on and will use, it is easy to go with the cheaper model that will almost, or may, do the job right.  But when you are using it, you are always wishing it was a little better for the task.  He said after the initial purchase, you don't miss that extra money you spent (maybe as much as half more) and you enjoy the work so much more having the right tool.  You respect the tool more, and don't have to gripe about the fact that it isn't quite what you wanted.  Plus you don't end up buying it twice when it breaks or just doesn't do the job.  

They are wise words, especially poignant coming from my father who is very tight with his money.  He can pinch a nickel until the buffalo craps.  I have never regretted purchases where I am getting what I want or need, rather than trying to shoe horn a less expensive version of the item to work for me.  I have many times regretted the latter.

I totally understand the money pinch, I am living it now more than ever.  But rather than getting something that might work for you, invest in a good antenna and borrow a handheld from me.  That way your not investing in something that might get you by, and you can save for the right tool for your application.  I am fairly confident that you will not be happy with a handheld with attached antenna wire in a loud series truck.  Plus it can be stressful to the antenna connector and can ruin the radio.  If you do like the handheld setup, you'll be confident buying that for yourself afterwards.

Sorry for the rant, do what you want, but the offer stands.  most important, go get that license.  you'll be glad you did.